DE20200633U1 - hybrid drive - Google Patents

Description

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HYBRID DRIVE

The present invention relates to a hybrid drive, in particular a hybrid drive for use in conjunction with a small combustion engine and an electric motor.

Conventionally, a vehicle is powered by an internal combustion engine. An internal combustion engine generates mechanical power that is transferred to wheels to drive the vehicle. Since internal combustion engines work by burning fuel, they produce exhaust gases that pollute the surrounding air. To protect the environment, electrically powered vehicles have been developed. These do not have internal combustion engines, but rather electric motors that are powered by batteries. In an electrically powered vehicle, electrical energy from a battery is converted into mechanical energy. Mechanical power is transferred to wheels via a transmission. However, batteries only have limited storage capacity, so that electrically powered vehicles have an insufficient range and generally do not meet requirements. This has led to the development of vehicles with hybrid drives consisting of an internal combustion engine and an electric motor. A suitable transmission device generates a varying torque, with the torques of the internal combustion engine and the electric motor being adapted to one another. This enables effective operation under various conditions, such as uphill and downhill, braking and starting. An ideal combination of both engines results in high performance and at the same time low emissions.

A variety of transmission devices provides a wide range of hybrid drives with different components and different effects. Currently, hybrid drives are used mainly in four-wheeled vehicles, where hundreds of systems have already been developed and there is strong competition between large companies.

Small vehicles powered by small engines, such as light motorcycles and compact cars, have limited space and are inexpensive. It is therefore difficult to install hybrid power transmission devices in small vehicles. Accordingly, hybrid power transmissions are rarely used in small vehicles. Despite some research activities and the publication of some inventions, hybrid power transmissions in small vehicles have only a limited range of applications.

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Several patents have been published concerning hybrid drives. They teach a planetary gear in which a sun gear and planetary gears are driven by a
combustion engine or an electric motor. Power is taken from a ring gear. Since there is no space between the combustion engine and the electric motor,
torque converter is installed, any change in speed leads to a

jerky behavior without the combustion engine and the electric motor being adapted to each other. When the combustion engine slows down, there is no way to interrupt the flow of torque. Such a transmission device is therefore not practical.

Thus, in order to operate a vehicle with a hybrid drive, it is necessary not only to accommodate the hybrid drive in a small space, but also to be able to
To operate the combustion engine and electric motor independently of each other, under
continuous mutual adaptation. It is also desirable to feed back electrical energy by operating the combustion engine and utilizing the kinetic energy of the vehicle. This will achieve a comprehensive effect of the hybrid drive. At the same time, this will set a development direction for small drives, such as those for light motorcycles and compact cars.

The main object of the present invention is to create an inexpensive hybrid drive.

In the present invention, an internal combustion engine and an electric motor are connected by a continuously variable transmission with a V-shaped cross-section drive belt and controlled by control devices so that the following functions are carried out:

1. Slow running or stopping of the combustion engine, leaving the electric motor running idle.

2. Slow running or stopping of the internal combustion engine, with the electric motor driving the vehicle forward.

3. Slow running or stopping of the internal combustion engine, with the electric motor driving the vehicle backwards.

4. The vehicle is driven by the combustion engine via the continuously variable transmission, with the electric motor running idle.

5. The vehicle is driven by the combustion engine via the continuously variable transmission, with the electric motor generating electricity.

6. Drive of the vehicle by the combustion engine via the continuously variable transmission, whereby

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the electric motor additionally drives the vehicle.

7. Slow running or stopping of the internal combustion engine, with the electric motor generating power due to kinetic energy of the slowing vehicle.

8. Running the internal combustion engine, where the electric motor runs idle and a generator connected to the internal combustion engine produces electricity while the vehicle is at rest.

By using a standard combustion engine and electric motor, the present invention creates a low-cost hybrid drive that allows flexible adaptation to different performance requirements and working conditions. The present invention can be used in conjunction with two-wheeled and four-wheeled vehicles
so that a wide range of applications is ensured.

Further advantages, features and possible applications of the present invention will become apparent from the following description of embodiments in conjunction with the drawings.

Fig. 1 is a schematic representation of the hybrid drive of the present

Invention in the first embodiment.

Fig. 2 is a schematic representation of the hybrid drive of the present
Invention in the second embodiment for use in connection with a

two-wheeled vehicle.
Fig. 3 is a schematic representation of the hybrid drive of the present

Invention in the third embodiment for use in connection with a four-wheeled vehicle.

Fig. 4 is a schematic representation of the hybrid drive of the present
Invention in the fourth embodiment for use in connection with a two-wheeled vehicle.

As shown in Fig. 1, the hybrid drive of the present invention in a first embodiment essentially comprises: a first motor 10; a primary

Power transmission 20; a continuously variable transmission 30 with a drive belt of V-shaped cross-section; a secondary drive shaft 40; and an electric motor 50. The first motor 10 drives a primary drive shaft 21 via the primary power transmission 20. The primary drive shaft 21 drives a rotary movement of the secondary drive shaft 40 via the continuously variable transmission 30. Finally, a transmission system drives a vehicle.

Any motor can be used as the first motor 10. In the figures, the first motor 10 is shown as an internal combustion engine. The primary transmission 20 has a crankshaft. A starter 22 and an electric generator 23 are attached to the primary transmission 20. The starter 22 is manually or electrically operated and serves to start the first motor 10. The generator 23 is driven by the first motor 10 and generates a relatively small electric current, as well as time signals of the rotation of the first motor 10.

The continuously variable transmission 30 comprises: a primary gear 31 on the primary drive shaft 21; a secondary gear 32 on the secondary drive shaft 40; and a drive belt 33 with a V-shaped cross section which runs over the primary gear 31 and the secondary gear 32. The primary gear 31 consists of two gear halves 311, 312 in the form of truncated cones with a gap between them. The gear half 311 can be moved slidably along the primary drive shaft 21. A blocking plate 34 is fixedly mounted on the primary drive shaft 21 adjacent an outer side of the gear half 311. A plurality of balls 35 are inserted into grooves in the outside of the wheel half 311 and thus lie between the outside of the wheel half 311 and the blocking plate 34. When the primary drive shaft 21 rotates, the balls 35 are driven radially outward by centrifugal forces until the blocking plate 34 blocks further radial movement of the balls 35. A resulting counterforce displaces the wheel half 311 along the primary drive shaft 21, thereby changing the width of the gap between the wheel halves 311, 312.

The secondary wheel 32 consists of two wheel halves 321, 322 in the form of truncated cones, between which there is a gap. The wheel half 321 can be moved in a sliding manner along the secondary drive shaft 40. Between the wheel half 321 and the secondary drive shaft 40 there is a cam wheel 36 and a return spring 37. As a result, when a torque load changes, the wheel half 321 moves along the secondary drive shaft 40, which changes the width of the gap between the wheel halves 321, 322.

The balls 35 and the cam wheel 36 ensure that the wheel halves 311, 312 of the primary wheel 31 and the wheel halves 321, 322 of the secondary wheel 32 move towards or away from each other, depending on the speed of the first motor 10 and the torque load on the secondary drive shaft 40. The drive belt 33 has a

Cross-section with inclined outer surfaces that correspond to the pitches of the wheel halves 311, 312 and 321, 322. By changing the gaps between the wheel halves 311, 312 and the wheel halves 321, 322, the circumference of the drive belt 33 on the primary wheel 31 and the secondary wheel 32 changes. The continuously variable transmission 30 thus continuously reduces speeds and ensures that the speed of the first motor 10 is adapted to the torque load.

The continuously variable transmission 30 is further provided with a clutch 60. The clutch 60 is seated on the primary drive shaft 21 or on the secondary drive shaft 40. In the illustrated embodiments, the clutch 60 is located between the primary drive shaft 21 and the wheel half 312. An outer side of the wheel half 312 is provided with a friction surface. The clutch 60 has a seat 61, several holding blocks 62 and several springs 63. The seat 61 is attached to the primary drive shaft 21. The holding blocks 62 are located within the friction surface of the wheel half 312, are connected to the seat 61 and are pressed against it by the springs 63. When the first motor 10 has reached a limit speed, the holding blocks 62 are pushed radially outward by centrifugal forces and press against the friction surface so that torque is transmitted from the primary drive shaft 21 to the primary wheel 31. The clutch 60 ensures that below a limit speed of the first motor 10 no torque is transmitted from the primary drive shaft 21 to the primary wheel 31. Only when the primary drive shaft 21 rotates faster than the limit speed, so that the holding blocks 62 mesh with the friction surface, is the primary wheel 31 driven by the primary drive shaft 21.'

The essential feature of the present invention is that the electric motor 50 is additionally connected to the secondary drive shaft 40. The electric motor 50 is electrically connected to a rechargeable battery 70 and is supplied with electrical energy by the latter in order to drive the secondary drive shaft 40. Conversely, the electric motor 50, when driven by the secondary drive shaft 40, generates electrical current which charges the battery 70. The secondary drive shaft 40 is rotated by the first motor 10 or by the electric motor 50 or by the first motor 10 and the electric motor 50 together. A combination of two drive sources, the first motor 10 and the electric motor 50, thus drives the vehicle.

As shown in Fig. 2, the present invention comprises in a second embodiment for use in connection with a two-wheeled vehicle a

sprocket 80 which is fitted on a free end of the secondary drive shaft 40. A chain 81 runs over the sprocket 80 to drive the vehicle. As shown in Fig. 3, the present invention in a third embodiment, also for use in connection with a two-wheeled vehicle, has a structure which is substantially the same as the structure of the first embodiment. In contrast thereto, an electric motor 5OA with an external rotor is used. The electric motor 5OA comprises: a stator 51A; a rotor 52A; and a wheel hub 53A which is attached to the free end of the secondary drive shaft 40 and is driven thereby. The rotor 52A is in the form of a drum and is attached to the secondary drive shaft 40 or the wheel hub 53A and is driven thereby. The stator 51A is fixedly inserted into a free space between the secondary drive shaft 40 and the rotor 52A without being connected to the secondary drive shaft 40. The use of the external rotor electric motor 50A of the third embodiment is particularly suitable for use in light motorcycles.

As shown in Fig. 4, in a fourth embodiment for use in connection with a four-wheeled vehicle, the present invention comprises a speed reduction gear 90 attached to the secondary drive shaft 40. The gear 90 drives a differential gear 91 having two driven axles 92 to which a left and a right wheel of the vehicle are attached.

The above-described structure has the following advantages: The continuously variable transmission with V-belt, with its ideal-converting characteristics, accommodates any torque load and adjusts the speed accordingly without causing any jerky changes in the speed. The present invention takes advantage of this, with the primary gear 31 rotating with the primary drive shaft 21 of the first motor 10 and the secondary gear 32 rotating with the secondary drive shaft 40 of the electric motor 50, so that a combined drive source is formed. The continuously variable transmission 30 smoothly adjusts the first motor 10 and the electric motor 50 to each other. By using standard control devices and sensors, such as a vehicle speed sensor, a speed sensor and a throttle sensor, the drive sources can be controlled individually to achieve an optimal combination. The underlying principle is explained below.

A. Parking the vehicle:

When the vehicle is parked with the first motor 10 running slowly, the clutch 60, by restricting speeds above the limit speed, does not transmit torque from the first motor 10 to the secondary drive shaft 40. The first motor 10 continues to run at a certain speed without moving the vehicle. By changing the support blocks 62, the limit speed can be varied. The electric motor 50 is held at rest by a control device so as not to move the vehicle.

B. Starting:

When starting, the vehicle moves slowly. When the first motor 10 moves the vehicle, it does so inefficiently. The electric motor 50, on the other hand, is capable of generating high torque at low speed. Therefore, in the present invention, a controller shuts off the first motor 10 and instead causes the electric motor 50 to drive the secondary drive shaft 40 and a transmission to move the vehicle. In this case, the electric motor 50 alone generates torque and accelerates the vehicle slowly.

C. Reversing:

For at least three-wheeled vehicles, the possibility of reversing is usually required. When reversing, the driving speed is low. Therefore, in this state, the first motor 10 is at rest or runs slowly, while the electric motor 50 rotates in reverse, thereby moving the vehicle in reverse. No reverse gear is required for this.

D. Driving at medium speed:

When the electric motor 50 is moving the vehicle at medium speed and additional power is needed to accelerate the vehicle, a controller causes the starter 22 to start the first motor 10. The first motor 10 is accelerated to a speed above the limit speed so that the clutch 60 engages and torque is transmitted to the secondary drive shaft through the continuously variable transmission 30 to match the electric motor 50. Thereafter, the electric motor 50 continues to run or is turned off so that no electrical energy is consumed while the first motor 10 runs in an effective operating range.

-E. Power generation at medium speed or high speed:

If the accumulator 70 is discharged while the first motor 10 is driving the vehicle, the electric motor 50 is switched to a generator function. The first motor 10

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is accelerated and the electric motor 50 generates electricity so that the accumulator 70 is charged under the control of a control device. Due to the torque-converting characteristics of the continuously variable transmission 30, the additional load caused by the electricity generation does not lead to a sudden change in speed. At the same time, the control device regulates the load caused by the electric motor 50 depending on the operating state of the first motor 10 so that no change in the behavior of the vehicle is noticeable.

F. Rapid acceleration:

If a throttle valve is opened rapidly to accelerate the vehicle or to provide increased power while the vehicle is being moved by the first motor 10, the electric motor 50 is switched on. Since the electric motor 50 is matched to the first motor 10, no jerky forces are felt.

G. Braking with battery charging:

When the vehicle brakes or drives downhill, the electric motor 50 is switched to generator operation. An inert magnetic field in the electric motor 50 increases the mechanical load, which is overcome by the remaining kinetic energy of the vehicle driving downhill or slowing down. The accumulator 70 is charged in the process. If the accumulator 70 is already fully charged, the braking of the vehicle is purely mechanical.

H. Driving at low speed:

If the vehicle is traveling at a speed lower than a preset value and the throttle valve is not opened so that there is a low load, a control device turns on the electric motor 50 to move the vehicle and turns off the first motor 10 so that the first motor 10 does not continue to run at a speed below the limit speed.

I. Stopping:

When the vehicle is stopped, for example at a traffic light, or rests for some time, the first motor 10 is switched off in order to minimize fuel consumption and the production of exhaust gases. At the same time, the electric motor 50 is prepared to set the vehicle in motion on request.

J. Driving at low speed while generating electricity:

While the vehicle is moving at low speed, the first motor 10 is switched off and the vehicle is driven by the electric motor 50. If the accumulator 70 is discharged in this state, the charge state is displayed and the starter 22 starts the first motor 10 automatically or by manual request. Its speed is increased in order to achieve adaptation to the speed of the secondary drive shaft 40. At the same time, the electric motor 50 is switched to the generation of electricity
In this state, the first motor 10 not only maintains the running speed but also rotates the electric motor 50 to generate electricity. After the accumulator is charged to a preset level, the first motor 10 is turned off and the electric motor 50 is turned on to drive the vehicle with minimal air pollution.

K. Power generation in a parked vehicle:

If the accumulator 70 is discharged when the vehicle is parked, the charge level is displayed and the starter 22 starts the first motor 10 after a manual request. The first motor 10 rotates at a relatively high speed, but without the clutch 60 engaging. The electric motor 50 is at rest. The first motor 10 drives the generator 23, which then generates a relatively low current to effect an emergency charge of the accumulator 70. If necessary, a control device switches off the first motor 10 as soon as a preset amount of exhaust gases recorded by a sensor is exceeded. In addition, an external circuit can be used to charge the accumulator.

L. Starting without battery:

If the accumulator 70 is completely discharged while the vehicle is at rest and the first engine 10 is switched off, the first engine 10 is started manually, for example by a kick starter. A control device then brings the first engine 10 to a higher speed so that the generator 23 generates current to charge the accumulator 70.

If the throttle valve is opened in this state, the first motor 10 is further accelerated and drives both the vehicle and the electric motor 50, so that a comparatively large current is generated and charges the accumulator 70. After the accumulator 70 is charged, the state D or F is switched over.

By operating in various modes as described above, the hybrid drive of the present invention adapts to each condition of the vehicle and selects an appropriate mode in which fuel consumption and air pollution are minimized and driving and acceleration are controlled as needed. When the vehicle

braked or stopped, neither noise nor exhaust gases are generated. The present invention also has a simple structure made of standard components and saves components in four-wheeled vehicles because no reverse gear is required. This significantly reduces costs while at the same time expanding possibilities. The applicability in two- and four-wheeled vehicles gives a wide range of possible applications. This results in a technical superiority of the
present invention among hybrid drives.

The foregoing explanation of the present invention, although it describes the features and advantages of the present invention by means of a detailed structural and
Functional description explained, only illustrative. Changes in detail,
in particular with regard to size, shape and arrangement of parts are feasible within the scope defined by the following claims.

Claims (11)

1. Hybrid drive, comprising:
a first motor having a primary drive shaft;
a secondary drive shaft driven by the primary drive shaft;
a continuously variable transmission between the primary drive shaft and the secondary drive shaft and provided with a drive belt so that torque is transmitted from the primary drive shaft to the secondary drive shaft;
a clutch fitted to the primary drive shaft or the secondary drive shaft and allowing or preventing the transmission of torque from the first motor to the secondary drive shaft; and
an electric motor connected to and driving or being driven by the secondary drive shaft and thereby generating electric current or being at rest. 2. Hybrid drive according to claim 1, wherein the continuously variable transmission further comprises:
a primary wheel having two wheel halves in the form of truncated cones spaced apart from each other;
a ball located outside an axis of rotation that controls the spacing of the wheel halves of the primary wheel;
a secondary wheel having two wheel halves in the form of truncated cones spaced apart from each other; and
a cam wheel with a spring that controls the distance between the wheel halves of the secondary wheel depending on the load;
where the drive belt runs over the primary wheel and the secondary wheel. 3. A hybrid drive according to claim 1, wherein the first motor is an internal combustion engine to which a starter for starting the first motor and a generator are attached, the generator being driven by the first motor and thereby generating electric current and time signals of a rotational movement of the first motor. 4. A hybrid drive according to claim 1, wherein the clutch comprises a seat, at least one retaining block and at least one spring. 5. A hybrid drive according to claim 1, wherein the electric motor is electrically connected to a rechargeable battery that serves as a power source to drive the secondary drive shaft. 6. A hybrid drive according to claim 1, wherein the secondary drive shaft is driven by the continuously variable transmission alone, by the electric motor alone, or by the continuously variable transmission and the electric motor together. 7. Hybrid drive according to claim 1, wherein the electric motor, in addition to a motor function, generates electrical current with which a storage battery is charged. 8. Hybrid drive according to claim 1, wherein the drive belt has a V-shaped cross-section. 9. Hybrid drive according to claim 2, wherein the drive belt has a V-shaped cross-section. 10. A hybrid drive according to claim 1, wherein the secondary drive shaft has a free end having a sprocket attached thereto over which a chain runs so that torque is transmitted from the secondary drive shaft. 11. A hybrid drive according to claim 1, wherein the secondary drive shaft has a free end to which a gear is attached that drives a differential gear having two driven axles to which a left and a right wheel of a vehicle are attached.